Thank you p45cal. The profile or census is done every end of quarter of the calenday year, so the profile date is March 31, 2019 while the comparison date is the previous end of quarter, that is Dec 31, 2018. I'm sorry for not providing the full details, otherwise so much guessing from good Samaritans like you would have been avoided. Taking cues from your formula, I came up with the following conditional formula, and it works fine.
=(VLOOKUP(DATEDIF($b14,$D12,"d"),$A$2:$D$10,4))<>$ D14
Any idea why range names do not work in conditional formatting?



Thanks also for the formula below, dispensing with the extra column computing the age in days and saving precious file space.